This invention relates to non destructive test apparatus and provides a free roving vehicle for carrying inspection instrumentation over a remote surface.
A vehicle according to the invention finds application in the inspection of a primary vessel of a construction of liquid metal cooled nuclear reactor of the pool kind. Such a nuclear reactor construction comprises a nuclear fuel assembly submerged in a pool of liquid metal coolant contained in the primary vessel which is housed in a concrete containment vault. In use the primary vessel is subject to irradiation and to severe thermal stress so that periodic inspection of the vessel is required to ensure its continued integrity. Inspection of the primary vessel is difficult because it must be carried out on its external surface by remotely operated apparatus.